Leighton Bracegirdle was born in Balmain, Sydney, on 31 May 1881. He was educated at Sydney High School and became a clerk. In 1898 he joined the New South Wales Naval Brigade as a cadet. Two years later he became a midshipman. Bracegirdle served with the New South Wales contingent in China during the Boxer Rebellion. In China, Bracegirdle was involved with other contingent members in defence of the towns they were assigned to and patrolling areas to prevent crime and banditry or in railway construction and maintenance. Many of the contingent ended up being mounted so that they could carry out these roles. After return to Australia on board the SS Chingtu with the rest of the contingent on 25 April 1901, Bracegirdle on leave from the Navy went to South Africa to seek service in the Boer War.

From approximately August 1901 until the end of the war he served with two South African irregular units. Records of his first service no longer exist but contrary to some reports he served first with the South African Irregular Horse (most probably South African Mounted Irregular Force). With this unit he was apparently wounded by a sniper when thrown from his horse. Upon recuperating he then joined the 4th battalion of the Railway Pioneer Regiment on 1 April 1902 and served until discharge at the end of June 1902. The RPR, being a combat pioneer unit was responsible for keeping rail lines open and sabotage repaired. It was an ideal posting to gain skills that would be important for his World War I service. He received the Queen's South African medal with clasps for his South African service. He returned to Australia after the war and continued to serve in the naval militia while working as a clerk.

In 1911 he joined the Royal Australian Navy as a lieutenant, serving as District Officer in Newcastle until the beginning of the First World War.

In August 1914 Bracegirdle enlisted in the Australian Naval and Military Expeditionary Force, serving as a staff officer in German New Guinea until the force was disbanded in February 1915. That month he was appointed commander of the 1st Australian Naval Bridging Train and was sent to Gallipoli to prepare for the British landings at Suvla Bay in August 1915. The unit was attached to IX British Corps and performed well under relentless shrapnel fire. It remained at Suvla, where Bracegirdle was wounded, until the end of the campaign. His were the last Australian troops on Gallipoli. He was twice mentioned in dispatches for distinguished service at Suvla. Having constructed the piers used during the British landing, the bridging train carried out maintenance duties; assisted with the landing of troops, stores, and ammunition; and finally assisted with the evacuation in December. After a period in hospital suffering from jaundice and malaria, Bracegirdle returned to his unit, which was now working on the Suez Canal. The train served with I Anzac Corps, operating on the Suez Canal. Late in April it was reassigned to IX Army Corps in the southern section where, in addition to controlling canal traffic and conveying military stores, it built substantial wharves for unloading heavy engines for the desert military railways. Bracegirdle was awarded the Distinguished Service Order in June and was mentioned in dispatches in September. In mid-December, during the advance into Palestine, his unit landed stores on the open coast of the Sinai Desert off El Arish. Bracegirdle received his third Mention in Despatches in July that year. The bridging train was disbanded at the beginning of 1917. Bracegirdle's command ended in March and he returned to Australia having been promoted to commander.

Between 1918 and 1921, Bracegirdle was District Naval Officer in Adelaide. This was followed by a similar posting in Sydney, which he held until 1923, when he was appointed Director of Naval Reserves. He had also been a president of the Commonwealth Coal Board in 1919-20.

In 1924 he received another promotion, to captain.

Bracegirdle was appointed military and official secretary to the Governor-General in 1931; his posting spanned the tenure of three governors-general and part of a fourth. He retired from the navy in 1945 having attained the rank of rear admiral. After his retirement from his post as official secretary to the Governor General in 1947 he was appointed K.C.V.O. Bracegirdle worked for BHP and held directorships in several other companies. He died on 23 March 1970 in Sydney.